Extracting the jet transport coefficient of cold nuclear matter from world data

Abstract We present the first global extraction of the jet transport coefficient ( q ˆ ) for cold nuclear matter within the framework of higher-twist expansion. The analysis takes into account the world data on transverse momentum broadening in semi-inclusive e-A deep inelastic scattering (DIS) and in Drell-Yan dilepton and heavy quarkonium production in p-A collisions, as well as the nuclear modification of the structure functions in DIS. The results of this work provide the first quantitative evidence for the universality and non-trivial scale dependence of the medium transport property, similar to that for nucleon structure as encoded in the standard parton distribution functions. We expect the extracted scale dependence of q ˆ for cold nuclear matter can be extended to precisely identify the fundamental property of quark gluon plasma.